This invention relates to the field of rocket launchers. In recent years there has been development of extremely lightweight, man portable anti-tank rocket launchers with minimum carry length. These launchers consist of thin-walled telescoping inner and outer tubes, with the telescoping aspect providing a minimum launcher carry length. Normally when the tubes are extended, the outer tube becomes the forward portion of the launcher and the inner tube the aft portion. Under these conditions the inner tube then withstands the greatest share of the rocket exhaust forces and the outer tube acts as a missile exhaust shield. These launchers have sights that are mounted on the outer tube only and a fixed alignment need not be maintained between the inner and outer tubes for sighting purposes. When the launch tubes are reversed wherein the inner tube becomes the forward launch tube and the outer tube becomes the aft tube a problem in sighting arises. One sight is mounted on each tube and some mechanism or device is necessary to hold the tubes against relative longitudinal and rotational movement with respect to each other when in the extended position.